This is where my TREMAC came from. Mine is adapted for a sbc, but I believe Mike Forte
http://www.fortesparts.com/ has them for almost any application. You can't compare a T-5 to a TREMAC except in basic design...and expense.

FORTE'S also handle most popular transmissions, including the FORD MOTORSPORT transmissions.
The T-5 came in later model Mustang, Thunderbird, Camaro and Firebird. They are different depending on original application. The TREMAC 3550 or TKO is a very heavy duty version.
In my TREMAC, I have the choice of three shift positions. It is capable of 500hp and almost as much torque. They cost over $2,000, so a T-5 is very appealing for a less high performance application. They can be found in your favorite junk yard by now.